Method of arranging a multiplicity of leds in packaging units, and packaging unit comprising a multiplicity of leds

ABSTRACT

A method of arranging a multiplicity of LEDs in packaging units includes defining a desired range for at least one photometric measurement variable for each of the packaging units; selecting an LED from the multiplicity of LEDs not yet arranged in one of the packaging units; measuring the at least one photometric measurement variable for the selected LED; equipping one of the packaging units containing fewer than N−1 LEDs with the selected LED; storing a measured value and a position of the selected LED in the packaging unit in a memory; repeating until the packaging units are equipped with N−1 LEDs; repeating and calculating the average value of the photometric measurement variable, equipping a packaging unit for which the calculated average value of the variable lies in a defined range with the selected LED; and storing the measured value and the position of the selected LED.

TECHNICAL FIELD

This disclosure relates to a method of arranging LEDs in packagingunits, and to a packaging unit comprising a multiplicity of LEDs.

BACKGROUND

On account of their high efficiency, LEDs are increasingly being used inLED lamps for general lighting or in automobile headlights. It is oftenthe case that a plurality of LED lamps are operated alongside oneanother, wherein the individual LED lamps can each contain a pluralityof LEDs.

For different LED lamps arranged alongside one another offer ahomogeneous appearance with regard to their brightness and/or theircolor, it is desirable for radiation emitted by the different LED lampsto have the same brightness and/or the same color locus in each case.However, during the manufacture of LEDs it cannot be ruled out thatsmall brightness or color deviations of the individual LEDs occur,particularly in the case of LEDs from different production series. Forthis reason, the LED manufacturer often groups LEDs prior to delivery(so-called “binning”), wherein a group of LEDs (the so-called “bin”) isdistinguished, for example, by the fact that all the LEDs in this grouphave the same brightness and/or the same color locus. If only LEDs froma single group are used during production of LED lamps, it is ensuredthat all luminaires equipped with the LEDs have the same brightnessand/or the same color locus. In this case, however, it is necessary forthe customer of the LED manufacturer, which customer processes theindividual LEDs further to form LED lamps, in each case to use only LEDsfrom the same LED group such that all the luminaires of differentproduction series have the same brightness and/or the same color locus.Alternatively, it would also be conceivable for a luminairemanufacturer, in equipping an LED lamp, to select in a targeted manner aplurality of LEDs from different LED groups having differentbrightnesses and/or color loci such that the luminaire containing aplurality of LEDs has overall the desired values for the brightnessand/or the color locus. This would have the advantage that the luminairemanufacturer could use LEDs from groups having different brightnessesand/or color loci, but on the other hand leads to an increasedproduction outlay since LEDs from different packaging units would haveto be used to equip an individual LED lamp.

It could therefore be helpful to provide a method of arranging LEDs in apackaging unit, which method achieves the effect that an LED componenthaving a predetermined number of LEDs fulfils a desired value range forat least one photometric measurement variable, wherein the outlay toequip the LED component with LEDs from the packaging unit is low.Furthermore, it could be helpful to provide an advantageous packagingunit comprising a multiplicity of LEDs.

SUMMARY

We provide a method for arranging a multiplicity of LEDs in packagingunits, including:

a) defining a desired value range for at least one photometricmeasurement variable for each of the packaging units, wherein an averagevalue of the photometric measurement variable for a fixed number of N≧3successive LEDs in the packaging units is intended to lie in the desiredvalue range;

b) providing the multiplicity of LEDs and the packaging units;

c) selecting an LED from the multiplicity of LEDs which is not yetarranged in one of the packaging units;

d) measuring the at least one photometric measurement variable for theselected LED;

e) equipping one of the packaging units, containing fewer than N−1 LEDswith the selected LED, wherein the LEDs are strung together in thepackaging unit in the equipping order;

f) storing a measured value of the at least one photometric measurementvariable and a position of the selected LED in the packaging unit in adata memory;

g) repeating c) to f), until all of the packaging units are equippedwith N−1 LEDs;

h) repeating c) and d) and calculating the average value of the at leastone photometric measurement variable, which respectively results for theN−1 LEDs last arranged in the packaging unit and the selected LED,wherein the calculation is carried out for all of the packaging units;

i) equipping a packaging unit for which the calculated average value ofthe at least one photometric measurement variable lies in a defineddesired value range with the selected LED, wherein the selected LED isarranged in the packaging unit such that it directly follows the LEDlast arranged in the packaging unit; or sorting out the selected LED ifthe calculated average value of the photometric measurement variabledoes not lie in the defined desired value range for any of the packagingunits;

j) storing the measured value of the at least one photometricmeasurement variable and the position of the selected LED in thepackaging unit in a data memory; and

k) repeating h) to j), until the packaging units are equipped with adesired total number of LEDs.

We also provide a packaging unit including a multiplicity of LEDs,wherein:

-   -   the LEDs are arranged in the packaging unit in an order;    -   an average value of at least one photometric measurement        variable for a number of N≧3 successive LEDs removed at an        arbitrary location of the packaging unit lies in a desired value        range for the at least one photometric measurement variable;    -   the packaging unit is identified with the number N; and    -   the total number of the LEDs arranged in the packaging unit is        greater than the number N at least by a factor of 20.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 8 show an illustration of an example of the method ofarranging a multiplicity of LEDs in packaging units on the basis ofschematically illustrated intermediate steps.

FIG. 9 shows a schematic illustration of packaging units each comprisinga multiplicity of LEDs.

DETAILED DESCRIPTION

We provide a method by which a multiplicity of LEDs are arranged in aplurality of packaging units.

Thus, a first step may involve defining a desired value range for atleast one photometric measurement variable for each of the packagingunits, wherein the average value of the photometric measurement variablefor a fixed number of N≧3 successive LEDs in the packaging units isintended to lie in the desired value range.

In one configuration, the desired value range and the fixed number N ofsuccessive LEDs for which the average value of the photometricmeasurement variable is intended to lie in the desired value range areidentical for the plurality of packaging units. By way of example, itcan be provided that in each case four successive LEDs intended to beremoved from one of the packaging units are intended to have an averagevalue of the photometric measurement variable which is intended to liein the desired value range. In this case, therefore, N=4 for all of thepackaging units.

Alternatively, however, it is also possible for the plurality ofpackaging units to differ in terms of the desired value range and/or thefixed number N of successive LEDs for which the average value of the atleast one photometric measurement variable lies in the desired valuerange. By way of example, it can be provided that three packaging unitsare equipped simultaneously, wherein the average value of thephotometric measurement variable in the first packaging unit for N₁=3successive LEDs is intended to lie in the desired value range. For thesecond packaging unit, the average value of the photometric measurementvariable, for example, for N₂=5 successive LEDs is intended to lie inthe desired value range, and for N₃=7 successive LEDs for the thirdpackaging unit. The number N of successive LEDs in the packaging unitfor which the average value of the photometric measurement variable isintended to lie in the desired value range is preferably definedaccording to the number of LEDs which the customer of the LEDmanufacturer removes from the packaging units for the purpose ofequipping optoelectronic components. If, with the LEDs from a packagingunit, for example, optoelectronic components are in each case intendedto be equipped with 5 LEDs, N=5 is defined for the packaging unit. Inthis case, the packaging unit is equipped by the method described belowsuch that 5 successive LEDs removed from the packaging unit at anarbitrary location in the order of their arrangement respectively havean average value of the photometric measurement variable which lies inthe predetermined desired value range.

In the method, the multiplicity of LEDs are provided, for example, in asupply container from which the LEDs can preferably be automaticallyremoved individually. The multiplicity of LEDs can comprise, forexample, more than 1000 or even more than 10000 LEDs. In particular, themultiplicity of LEDs can be a production series of LEDs of identicaltype which are intended to be arranged in packaging units prior todelivery to a customer of the LED manufacturer. Furthermore, theplurality of packaging units in which the LEDs are intended to bearranged are provided.

An LED which is not yet arranged in one of the packaging units may beselected from the multiplicity of LEDs. The selected LED is, forexample, an arbitrary LED removed from the supply container.

Afterwards, the at least one photometric measurement variable ismeasured for the selected LED.

In a further step, one of the packaging units which still contains fewerthan N−1 LEDs is equipped with the selected LED. The LEDs are strungtogether in the packaging units in each case in the equipping order. Inother words, the LEDs are arranged sequentially in the packaging units,wherein the LED first arranged in the packaging unit is arranged at afirst location, the LED arranged as second in the packaging unit isarranged at a second location, the LED arranged as third is arranged ata third location, and so on. The LEDs can therefore be removed againfrom the packaging unit in the order or the opposite order in which thepackaging unit was equipped with the LEDs.

The measured value of the at least one photometric measurement variableand the position of the selected LED in the packaging unit areadvantageously stored in a data memory.

The steps of selecting an LED, measuring the at least one photometricmeasurement variable of the selected LED, equipping one of the packagingunits with the selected LED and storing the measured value and theposition of the selected LED are subsequently repeated until all of thepackaging units are equipped with N−1 LEDs.

Afterwards a further LED not yet arranged in one of the packaging unitsmay be selected, and the at least one photometric measurement variablemay be measured for the selected LED.

This is followed by calculating the average value of the at least onephotometric measurement variable which respectively results for the N−1LEDs last arranged in the packaging unit and the selected LED, whereinthis calculation is preferably carried out for all of the packagingunits. For this purpose, the measured values of the N−1 LEDs lastarranged in the respective packaging unit are read out from the datamemory. A check is made to determine whether, for at least one packagingunit, the number of N LEDs, which results from addition of the selectedLED to the N−1 LEDs last arranged in the packaging unit, has an averagevalue of the at least one photometric measurement variable that lies inthe defined desired value range.

In a further step, a packaging unit is advantageously equipped with theselected LED for which the average value of the at least one photometricmeasurement variable calculated in this way lies in the previouslydefined desired value range. In this way, it is ensured that the N LEDslast arranged in the packaging unit have an average value of thephotometric measurement variable which lies in the defined desired valuerange. In this method step, the selected LED is arranged in thepackaging unit such that it directly follows the LED last arranged inthe packaging unit. The LEDs are therefore strung together in theequipping order.

If the average value of the at least one photometric measurementvariable for the N−1 LEDs last arranged in the packaging used and theselected LED does not lie in the previously defined desired value rangefor any of the packaging units, the selected LED cannot be assigned toany of the packaging units, and is sorted out. The LEDs sorted out arepreferably stored in an intermediate store or fed to the supplycontainer again since they can possibly be assigned to one of thepackaging units in a later method step.

The measured value of the at least one photometric measurement variableand the position of the selected LED in the packaging unit areadvantageously stored in the data memory.

The steps of selecting an LED, calculating the average value of thephotometric measurement variable, equipping a packaging unit with theselected LED and storing the measured value and the position, or ifappropriate sorting out the LED, are subsequently repeated until thepackaging units are equipped with the desired total number of LEDs.

The packaging units are advantageously equipped with LEDs such that ineach case a number of exactly N LEDs have an average value of the atleast one photometric measurement variable which lies in the previouslydefined desired value range. Therefore, if exactly N successive LEDs areremoved from the packaging unit, it is ensured that the average value ofthe photometric measurement variable for this number of N LEDs lies inthe predetermined desired value range. When removing the LEDs from thepackaging unit, it is not important from which location of the packagingunit the first LED of the sequence is removed. In particular, theaverage value of the at least one photometric measurement variable of asequence of exactly N successive LEDs lies in the predetermined desiredvalue range even when the LEDs are removed from the packaging unit inthe opposite order to the equipping order. Furthermore, the averagevalue of integer multiples of the number of N LEDs also lies in thedesired value range. A packaging unit which is identified with thenumber N and is provided to equip components with N LEDs can thereforealso be used to equip components with 2N LEDs, 3N LEDs and so on.

The fact that in each case exactly N successive LEDs, on account of themethod described here for arrangement in the packaging unit, definitelyhave an average value of the photometric measurement variable in thedesired value range does not, of course, rule out the fact that this canalso be the case for a different number of LEDs in the packaging unit.

The method described herein to arrange LEDs in packaging units isadvantageous particularly when the packaging units are provided to equipoptoelectronic components each having a fixed number of N LEDs, whereinthe N LEDs on average have to comply with a desired value for aphotometric measurement variable. In particular, the arrangement of LEDsas described herein is advantageous in packaging units to equipcomponents in which at least slight differences in the at least onephotometric measurement variable of individual LEDs can be affordedtolerance if the average value of the N LEDs fulfils the desired valueof the at least one photometric measurement variable. This is the case,for example, in optoelectronic components in which the plurality ofLEDs, for example, on account of a light-diffusing cover, are notindividually perceptible or are individually perceptible only withdifficulty.

Advantageously, the at least one photometric measurement variable is thebrightness of the LEDs. In this case, the LEDs are advantageouslyarranged in the packaging units in such a way that a sequence of Nsuccessive LEDs in each case has on average a brightness which lies inthe defined desired value range.

Further, the at least one photometric measurement variable may be thecolor locus of the LEDs. The color locus can be specified, inparticular, by the coordinates C_(x) and C_(y) in the CIE chromaticitydiagram. In this configuration, the average value of the colorcoordinates C_(x), C_(y) of N successive LEDs in the packaging unitslies in each case in the defined desired value range. Consequently, thisfixed number of N LEDs has the same color impression in each case.

It is possible for a plurality of photometric measurement variables tobe used for the arrangement of the LEDs in the method. Particularlypreferably, the photometric measurement variables are both thebrightness and the color locus of the LEDs. In this configuration,therefore, the LEDs are arranged in the packaging units such that, for apredetermined number of N LEDs, both the average value of the brightnessand the average values of the color coordinates lie in predetermineddesired value ranges. In this way, it is ensured that a fixed number ofN successive LEDs meet the requirements in respect of a predeterminedbrightness and a predetermined color locus.

As an alternative and/or in addition to the brightness and/or the locus,it is also possible to use another photometric measurement variable inthe method to arrange the LEDs in the packaging units in a targetedmanner. By way of example, the photometric measurement variable can bethe color rendering index CRI or the wavelength λ_(max) of the intensitymaximum of the LED. Furthermore, it is also possible to use, in additionto the at least one photometric measurement variable, an electricalmeasurement variable to arrange the LEDs in the packaging unit. Theelectrical measurement variable can be, for example, the forward voltageU_(f) of the LEDs.

In the method, the number of packaging units is preferably at leastfour. By way of example, four to ten packaging units can be equippedsimultaneously.

The packaging units of the LEDs can be, in particular, rolls. The LEDsare preferably fixed on a tape on the roll such that they can easily beremoved from the roll. The LEDs can be removed from the roll in a simplemanner in the order in which the roll was equipped with the LEDs or inthe opposite order with respect thereto.

Preferably, the packaging units are identified with the number N ofsuccessive LEDs for which the average value of the at least onephotometric measurement variable lies in the desired value range. Acustomer of the LED manufacturer, which customer uses the packagingunits for equipping optoelectronic components, can therefore infer fromthe packaging unit what number N of successive LEDs have an averagevalue of the at least one photometric measurement variable which lies inthe desired value range. To equip optoelectronic components each havinga number of N LEDs, it is therefore possible to select a packaging unitidentified with the value N.

Preferably, the packaging units are identified with the at least onephotometric measurement variable and the associated desired value range.

The number N of LEDs for which the average value of the at least onephotometric measurement variable lies in the desired value range ispreferably 3 to 25, particularly preferably 3 to 15.

The total number of the LEDs arranged in the packaging units isadvantageously significantly greater than the number N. Preferably, thetotal number of the LEDs arranged in the packaging units is greater thanthe number N at least by a factor of 20, a factor of 100 or even afactor of 500.

The total number of the LEDs arranged in the packaging units isadvantageously at least 500 in each case. Preferably, the total numberof the LEDs arranged in the packaging units is in each case at least1000 or even at least 5000. By way of example, the packaging units cancontain 500 to 20000 LEDs.

Furthermore, a packaging unit comprising a multiplicity of LEDs isspecified in which the LEDs were arranged by the advantageous methodsdescribed herein.

Preferably, the packaging unit comprises a multiplicity of LEDs, whereinthe LEDs are arranged in an order in the packaging unit. The averagevalue of at least one photometric measurement variable for a number ofN≧3 successive LEDs, removed at an arbitrary location of the packagingunit lies in a desired value range for the at least one photometricmeasurement variable, wherein the packaging unit is identified with thenumber N. The total number of the LEDs arranged in the packaging unit isadvantageously greater than the number N at least by a factor of 20.

Further advantageous configurations of the packaging unit can beinferred from the description of the methods.

The methods of arranging a multiplicity of LEDs in packaging units andthe packaging unit are explained in greater detail below on the basis ofexamples in association with FIGS. 1 to 9.

Identical or identically acting constituent parts are in each caseprovided with the same reference symbols in the figures. The illustratedconstituent parts and also the size relationships of the constituentparts among one another should not be regarded as true to scale.

With the methods described herein, a multiplicity of LEDs, for example,a production series produced by an LED manufacturer, are packaged inpackaging units to be delivered to a customer, for example.

As illustrated in FIG. 1, the packaging units can be rolls R₁, R₂, R₃,for example. The rolls each have a tape 1 on which the LEDs can befixed. To simplify the illustration, the method is illustrated on thebasis of an example comprising three packaging units R₁, R₂, R₃. In themethods, however, it is also possible to use more packaging units,preferably at least four packaging units being used.

In the methods, it is provided that, in each of the M packaging units,where M is the number of packaging units, a fixed number N_(m) (m=1 toM) of successive LEDs have an average value of at least one photometricmeasurement variable which lies in a predetermined desired value range.

The number N_(m) can be different for the packaging units which areequipped simultaneously. By way of example, in the case of the exemplaryembodiment illustrated in FIG. 1, a first packaging unit R₁, for whichN₁=3 is defined, a second packaging unit R₂, for which N₂=4 is defined,and a third packaging unit R₃, for which N₃=6 is defined, aresimultaneously equipped with LEDs. The number N_(m) can therefore bedetermined separately for all of the packaging units m=1 to M.Alternatively, it would also be possible for N_(m) to be identical forall of the packaging units.

Furthermore, a desired value range for at least one photometricmeasurement variable is defined for each of the packaging units R₁, R₂,R₃ which desired value range is intended to be fulfilled by the averagevalue of the respective N_(m) LEDs. The photometric measurement variablecan be, in particular, the brightness Φ. Advantageously, an interval[Φ_(min), Φ_(max)]_(m) for m=1 to M as desired value range is definedfor each of the packaging units, where Φ_(min) is the permissibleminimum brightness and Φ_(max) is the permissible maximum brightness. Itis possible for the desired value range to be identical for all of thepackaging units. Alternatively, however, it is also possible to definedifferent desired value ranges for the packaging units.

Advantageously, one or a plurality of further photometric measurementvariables may be used to arrange the LEDs in the packaging units. Inaddition or as an alternative to the brightness, in particular the colorlocus of the LEDs can be used as the photometric measurement variable.The color locus of an LED can be specified, for example, by the colorcoordinates C_(x) and C_(y) in the CIE chromaticity diagram. In theexample described here, advantageously both the brightness Φ and thecolor coordinates C_(x), C_(y) are used as photometric measurementvariables for the arrangement of the LEDs in the packaging units. In thesame way as for the brightness Φ, a desired value range [C_(x,min),C_(x,max)]_(m) and [C_(y,min), C_(y,max)]_(m) for m=1 to M isrespectively defined for the color coordinates C_(x) and C_(y) as well.The desired value ranges for the color coordinates can be identical forall of the packaging units or have different values. The defined numbersN_(m) and the desired value ranges are advantageously stored in a datamemory 6.

As illustrated in FIG. 2, the multiplicity of LEDs 2 intended to bearranged in packaging units are provided in a supply container 3, forexample, from which the LEDs 2 can be individually removed. In themethod, the LEDs 2 are successively removed from the supply container 3and distributed among the plurality of packaging units.

Afterwards, as illustrated schematically in FIG. 3, the at least onephotometric measurement variable is measured for a selected LED 2. Forthis purpose, the radiation 4 emitted by the LED 2 is measured, forexample, by a spectral photometer 5 and/or a photodiode. In the exampledescribed here, the brightness Φ and the color coordinates C_(x), C_(y)of the LED 2 are measured. Alternatively, however, it would also bepossible for a different photometric measurement variable to bemeasured, for example, the wavelength λ_(max) of the intensity maximumand/or the color rendering index (CRI). Furthermore, it is also possiblefor an electrical measurement variable of the LED 2, for example, theforward voltage U_(f), to be measured in addition to the at least onephotometric measurement variable. The measured value of the at least onephotometric measurement variable is stored in a data memory. In theexample illustrated here, therefore, the brightness Φ and the colorcoordinates C_(x), C_(y) for the selected LED 2 are stored in a datamemory 6.

In a further method step illustrated schematically in FIG. 4, theselected LED 2 is assigned to one of the packaging units R₁, R₂, R₃.First, each of the packaging units is equipped with LEDs until thepackaging units R₁, R₂, R₃ each comprise N_(m)−1 LEDs. That is to saythat, first, the number of LEDs arranged in each of the packaging unitsis such that the packaging units each have one LED fewer than thepreviously defined number N_(m) of successive LEDs which are intended tohave, in the packaging unit, an average value of the at least onephotometric measurement variable which lies in the defined desired valuerange. As illustrated in FIG. 4, the first selected LED 2 is arranged,for example, as first LED on the roll R₁.

After arrangement of the LED 2 at a first location of the roll R₁, theposition of the LED 2 and the associated photometric measurementvariables Φ, C_(x), C_(y) are advantageously stored in the data memory6. The position is noted as P_(m,k), for example, where m indicates thenumber of the packaging unit and k indicates the number of the LED 2 inthe packaging unit. The first LED of the first packaging unit thereforehas the position P_(1,1). Furthermore, the fact that a number of z₁=1LEDs is now arranged in the packaging unit R₁ is stored in the datamemory 6.

In the same way, further LEDs 2 are successively removed from the supplycontainer, the photometric measurement variables are measured and theLEDs are assigned to the packaging units R₁, R₂, R₃. Until the numberN_(m)−1 is reached in each of the packaging units R₁, R₂, R₃, theassignment of the respectively selected LED 2 to one of the packagingunits does not have to be effected according to a fixed rule. Only thecondition that for the time being none of the packaging units isequipped with more than N_(m)−1 LEDs has to continue to be fulfilled.Consequently, the packaging units R₁, R₂, R₃ can be equipped with LEDsup to this number of LEDs 2 in the packaging units, for example,successively or according to the random principle. It is also possible,however, for a selection in respect of which of the packaging units R₁,R₂, R₃ is assigned the respective selected LED 2 already to be effectedon the basis of the measured photometric measurement variables.

FIG. 5 schematically illustrates an intermediate step of the method inwhich the first packaging unit R₁ has already been equipped with twoLEDs and the second packaging unit R₂ has been equipped with three LEDs.Since the value N₁=3 was defined for the first packaging unit R₁, thefirst packaging unit R₁ has already been equipped with N₁−1=2 LEDs.Since the value N₂=4 was defined for the second packaging unit R₂, thesecond packaging unit R₂, too, has already been equipped with N₂−1=3LEDs. Consequently, the selected LED 2 is arranged in the thirdpackaging unit R₃, which contains only one LED prior to being equippedwith the additional LED 2, such that the number of LEDs in the thirdpackaging unit R₃ is still less than N₃₋₁=5. After the arrangement ofthe selected LED 2 at the second location of the packaging unit R₃, thephotometric measured values Φ, C_(x), C_(y) of the LED 2 are assigned tothe position P_(3,2) of the LED 2 and these values and also the numberz₃=2 of the LEDs in the third packaging unit R₃ are stored in the datamemory 6.

FIG. 6 illustrates an intermediate step of the method in which thepackaging units R₁, R₂, R₃ have already been equipped respectively withN_(m)−1 LEDs. The assignment of a further selected LED 2, for which thebrightness Φ and the color coordinates C_(x), C_(y) were measured, toone of the packaging units R₁, R₂, R₃ is then effected such that theaverage value of the photometric measurement variables which wouldresult if the additional LED 2 were added to the N_(m)−1 LEDs alreadypresent is first calculated for all of the packaging units. Thecalculated average values of the photometric measurement variables arethen compared to the desired value ranges previously defined for thepackaging units. Therefore, for each packaging unit a check is made todetermine whether the average value

$\Phi_{avg} = {\frac{1}{N_{m\;}}{\sum\limits_{k = {z_{m} - N_{m} + 1}}^{k = {z_{m} + 1}}\Phi_{k}}}$

lies in the desired value range [Φ_(min), Φ_(max)]_(m) defined for thepackaging unit. In the same way, a check is made to determine whetherthe average values

$C_{x},_{avg}{= {{\frac{1}{N_{m}}{\sum\limits_{k = {z_{m} - N_{m} + 1}}^{k = {z_{m} + 1}}{C_{x,k}\mspace{14mu} {and}\mspace{14mu} C_{y,{avg}}}}} = {\frac{1}{N_{m}}{\sum\limits_{k = {z_{m} - N_{m} + 1}}^{k = {z_{m} + 1}}C_{y,k}}}}}$

lie in the previously defined desired value ranges [C_(x,min),C_(x,max)]_(m) and [C_(y,min), C_(y,max)]_(m).

If the calculated average values for one of the m=1 to M packaging unitslie in the previously defined desired value ranges, the selected LED isarranged as the next LED in the packaging unit. In the example in FIG.6, this is the case, for example, for the second packaging unit R₂ suchthat the selected LED 2 is arranged as the fourth LED in the secondpackaging unit R₂. The first four LEDs now arranged in the secondpackaging unit R₂ therefore fulfil the condition that the average valuesof the photometric measurement variables Φ_(avg), C_(x,avg) andC_(y,avg) lie in the desired value ranges defined for said packagingunit. After the LED 2 has been arranged as the fourth LED in the secondpackaging unit R₂, the position P_(2,4) with the associated photometricmeasurement variables Φ, C_(x), C_(y) and the updated number z₂=4 LEDsin the second packaging unit R₂ are stored in the data memory 6.

If, for the selected LED 2, the calculated average values of thephotometric measurement variables do not lie in the previously defineddesired value ranges for any of the packaging units R₁, R₂, R₃, theselected LED 2 can be stored in an intermediate store 7, for example,such that it can possibly be assigned to one of the packaging units R₁,R₂, R₃ at a later point in time. Furthermore, the case can also occur inwhich the calculated average values of the photometric measurementvariables lie in the defined desired value ranges for a plurality ofpackaging units. In this case, therefore, it would be possible to assignthe selected LED 2 to a plurality of packaging units. In this case, theassignment of the selected LED 2 to one of the suitable packaging unitscan be effected according to the random principle or according to apreviously defined priority. By way of example, it can be definedbeforehand that the selected LED 2 is in this case assigned to thatpackaging unit which still has the smallest number of LEDs.

The LEDs 2 subsequently selected from the supply container are assignedto the packaging units R₁, R₂, R₃ in the same way, wherein in each casethe N_(m)−1 LEDs last arranged in the respective packaging unit and therespectively selected LED 2 are used for the calculation of the averagevalues of the photometric measurement variables. FIG. 7 illustrates e.g.an intermediate step in which, prior to the addition of the selected LED2, the first packaging unit R₁ has been equipped with eight LEDs, thesecond packaging unit R₂ has been equipped with seven LEDs and the thirdpackaging unit R₃ has been equipped with nine LEDs. For the calculationof the average value of the photometric measurement variables, the twoN₁−1=2 LEDs last added, that is to say the seventh and eighth LEDs, andthe selected LED 2 are then used in the case of the first packagingunit. In the case of the second packaging unit, the N₂−1=3 LEDs lastarranged in the packaging unit, that is to say the fifth, sixth andseventh LEDs, and the selected LED 2 are used for the calculation. Inthe case of the third packaging unit, the N₃−1=5 LEDs last arranged insaid packaging unit, that is to say the fifth, sixth, seventh, eighthand ninth LEDs, and the selected LED 2 are used. During the calculationit emerges, for example, that the selected LED 2 in combination with thefive LEDs last arranged in the third packaging unit R₃ has averagevalues of the photometric measurement variables which lie in thepreviously defined desired value ranges. In this case, therefore theselected LED 2 is arranged at the tenth location in the third packagingunit R₃. Consequently, the position P_(3,10), the associated photometricmeasurement variables Φ, C_(x), C_(y) and the updated number of z₃=10LEDs in the third packaging unit R₃ are stored in the data memory 6.

This type of assignment of the respectively selected LED 2 to one of thepackaging units R₁, R₂, R₃ ensures that the average values of thephotometric measurement variables for the previously defined numberN_(m) of successive LEDs definitely lie in the desired value ranges, tobe precise independently of the location of the packaging units R₁, R₂,R₃ from which the N_(m) successive LEDs are removed. In this case, it isalso unimportant whether the N_(m) successive LEDs are removed in theorder in which they were arranged in the packaging unit, or in theopposite order.

FIG. 8 illustrates an intermediate step in which, after the intermediatestep carried out in FIG. 7, a further selected LED 2 is intended to beassigned to one of the packaging units R₁, R₂, R₃. In this case, itemerges, for example, that the condition that the N_(m)−1 LEDs lastarranged in the respective packaging unit in combination with theadditional selected LED 2 yield average values of the photometricmeasurement variables which lie in the previously defined desired valueranges is not fulfilled for any of the packaging units R₁, R₂, R₃. Inthis case, therefore, the selected LED 2 is not assigned to any of thepackaging units, but rather is stored in the intermediate store 7.Alternatively, it would also be possible to place the LED 2 again intothe supply container from which it was removed. The LED 2 stored in theintermediate store 7 or the supply container can be assigned to one ofthe packaging units at a later point in time.

The method described above is continued until all of the packaging unitsR₁, R₂, R₃ are equipped with the desired number of LEDs. FIG. 9illustrates the three packaging units R₁, R₂, R₃, for example, afterthey were each equipped with a multiplicity of LEDs 2. To simplify theillustration, only twelve LEDs 2 in each case are illustrated for eachpackaging unit. In actual fact, the preferred number of LEDs 2 arrangedin the packaging units R₁, R₂, R₃ is in each case at least 500, at least1000 or even at least 5000 LEDs. Typically, for example approximately500 to 20000 LEDs 2 are arranged on a roll functioning as a packagingunit R₁, R₂, R₃.

In one configuration of the packaging units R₁, R₂, R₃, the total numberof the LEDs 2 arranged in the packaging units is greater at least by afactor of 20 than the number N_(m) of successive LEDs, for which theaverage value of the photometric measurement variables lies in thedesired value range. Particularly preferably, the total number of theLEDs 2 arranged in the packaging units R₁, R₂, R₃ is greater than thenumber N_(m) by at least a factor of 100 or even by at least a factor of500. The number N_(m) of successive LEDs 2 which fulfil theabovementioned conditions for the average value of the at least onephotometric measurement variable is preferably 3 to 25. The packagingunits R₁, R₂, R₃ are preferably in each case identified with the numberN_(m). Particularly preferably, the packaging units R₁, R₂, R₃ are alsoidentified with the at least one photometric measurement variable, forexample, the brightness Φ and the color locus C_(x), C_(y), and theassociated desired value ranges.

N_(m) LEDs can be removed from the fully equipped packaging units R₁,R₂, R₃ from an arbitrary location, wherein the average values of thebrightness Φ and of the color loci C_(x), C_(y) for this number of LEDsdefinitely lie in the desired value ranges. By way of example, asindicated in FIG. 8, the third to fifth LEDs could be removed from thefirst packaging unit R₁, the sixth to ninth LEDs could be removed fromthe second packaging unit R₂ or the second to sixth LEDs could beremoved from the third packaging unit.

Our methods and packaging units are not restricted by the description onthe basis of the examples. Rather, this disclosure encompasses any novelfeature and also any combination of features, which in particularincludes any combination of features in the appended claims, even if thefeature or combination itself is not explicitly specified in the claimsor examples.

1-15. (canceled)
 16. A method of arranging a multiplicity of LEDs inpackaging units, comprising: a) defining a desired value range for atleast one photometric measurement variable for each of the packagingunits, wherein an average value of the photometric measurement variablefor a fixed number of N≧3 successive LEDs in the packaging units isintended to lie in the desired value range; b) providing themultiplicity of LEDs and the packaging units; c) selecting an LED fromthe multiplicity of LEDs which is not yet arranged in one of thepackaging units; d) measuring the at least one photometric measurementvariable for the selected LED; e) equipping one of the packaging units,containing fewer than N−1 LEDs with the selected LED, wherein the LEDsare strung together in the packaging unit in the equipping order; f)storing a measured value of the at least one photometric measurementvariable and a position of the selected LED in the packaging unit in adata memory; g) repeating c) to f), until all of the packaging units areequipped with N−1 LEDs; h) repeating c) and d) and calculating theaverage value of the at least one photometric measurement variable,which respectively results for the N−1 LEDs last arranged in thepackaging unit and the selected LED, wherein the calculation is carriedout for all of the packaging units; i) equipping a packaging unit forwhich the calculated average value of the at least one photometricmeasurement variable lies in a defined desired value range with theselected LED, wherein the selected LED is arranged in the packaging unitsuch that it directly follows the LED last arranged in the packagingunit; or sorting out the selected LED if the calculated average value ofthe photometric measurement variable does not lie in the defined desiredvalue range for any of the packaging units; j) storing the measuredvalue of the at least one photometric measurement variable and theposition of the selected LED in the packaging unit in a data memory; andk) repeating h) to j), until the packaging units are equipped with adesired total number of LEDs.
 17. The method according to claim 16,wherein the at least one photometric measurement variable is brightnessand/or locus.
 18. The method according to claim 16, wherein the numberof packaging units is at least
 4. 19. The method according to claim 16,wherein the packaging units are rolls.
 20. The method according to claim16, wherein the packaging units are identified with the number N ofsuccessive LEDs for which the average value of the at least onephotometric measurement variable lies in the desired value range. 21.The method according to claim 16, wherein the packaging units areidentified with the at least one photometric measurement variable andthe desired value range.
 22. The method according to claim 16, whereinthe number N is 3 to
 25. 23. The method according to claim 16, whereinthe total number of the LEDs arranged in the packaging units is greaterthan the number N at least by a factor of
 20. 24. The method accordingto claim 16, wherein the total number of the LEDs arranged in thepackaging units is at least
 500. 25. A packaging unit comprising amultiplicity of LEDs, wherein: the LEDs are arranged in the packagingunit in an order; an average value of at least one photometricmeasurement variable for a number of N≧3 successive LEDs removed at anarbitrary location of the packaging unit lies in a desired value rangefor the at least one photometric measurement variable; the packagingunit is identified with the number N; and the total number of the LEDsarranged in the packaging unit is greater than the number N at least bya factor of
 20. 26. The packaging unit according to claim 25, whereinthe at least one photometric measurement variable is brightness and/orcolor locus.
 27. The packaging unit according to claim 25, wherein thepackaging unit is a roll.
 28. The packaging unit according to claim 25,wherein the number N is 3 to
 25. 29. The packaging unit according toclaim 25, wherein the total number of the LEDs arranged in the packagingunits is at least
 500. 30. The packaging unit according to claim 25,wherein the packaging unit is identified with the at least onephotometric measurement variable and the desired value range.